Side effect of cyclosporine A is:

Correct Answer: C

Rationale: The correct answer is C: GI disturbance. Cyclosporine A is known to cause gastrointestinal (GI) disturbances as a common side effect, including nausea, vomiting, abdominal pain, and diarrhea. This is due to its impact on the digestive system. Choice A (Diarrhea) is too specific and not the most common side effect. Choice B (Headache) is not a typical side effect of cyclosporine A. Choice D (Immunosuppression) is the intended therapeutic effect of cyclosporine A, not a side effect. Therefore, C is the correct choice based on the common side effects associated with cyclosporine A.

Correct Answer: C

Rationale: The correct answer is C. Gemfibrozil (Lopid) has not been shown to reduce mortality associated with heart disease. This statement is false as fibric acid derivatives, including gemfibrozil, primarily work by lowering triglycerides and increasing HDL cholesterol levels, which may help in reducing the risk of heart disease but not mortality directly. Choices A, B, and D are all true statements about fibric acid derivatives. A: Clofibrate is indeed used for Type III hyperlipidemia. B: Gemfibrozil increases HDL cholesterol and lowers LDL cholesterol. D: Gemfibrozil is generally well tolerated with common side effects being gastrointestinal upset and myopathy.

Correct Answer: B

Rationale: The correct answer is B: Metastatic calcifications. Vitamin D3 can lead to hypercalcemia, causing calcium to deposit in soft tissues like blood vessels and kidneys, leading to metastatic calcifications. Choice A is incorrect because vitamin D deficiency, not excess, causes defective bone mineralization. Choice C is incorrect as vitamin D toxicity primarily affects calcium levels, not the liver. Choice D is incorrect as nephrolithiasis is more commonly associated with excess intake of calcium supplements, not vitamin D3.

Correct Answer: B

Rationale: Step 1: Plicamycin inhibits RNA synthesis in cancer cells, leading to myelosuppression. Step 2: Myelosuppression results in decreased production of blood cells, causing anemia, thrombocytopenia, and neutropenia. Step 3: Diarrhea is not a common adverse effect of plicamycin. Step 4: Nephrolithiasis and metastatic calcifications are not directly associated with plicamycin use.

Correct Answer: B

Rationale: The correct answer is B: Enlarged uptake of the drug by a microorganism. This is incorrect because mechanisms of bacterial resistance involve reducing the uptake of the drug (choice D), modifying the drug's target (choice C), and actively transporting the drug out of the microorganism or hydrolyzing it with enzymes (choice A). Enlarged uptake would actually make the bacteria more susceptible to the antimicrobial agent, not resistant.